Pilot burner and flame retaining means



April 1, 19 2 LE ROY A. M GUIRE PILOT BURNER AND FLAME RETAINING MEANS Filed Feb. 16, 1949 INVENTOR RNEY Patented Apr. 1, 1952 PILOT BURNER AND FLAME RETAINING MEANS Le Roy A. McGuire, Leonardo, N. J., assignor to Peabody Engineering Corporation, New York, N. Y., a corporation of New York Application February 16, 1949, Serial No. 76,770

2 Claims.

This invention relates to gas burners and more particularly to a burner tip having novel and improved characteristics.

An object is to provide a tip which will ignite and retain its flame even in a strong blast of air.

Another object is to provide a tip for burning gases of different B. t. u. contents.

Another object is to provide a novel and improved tip for burner ignitors which is dependable and stable in operation.

Various other objects and advantages will be apparent as the nature of the invention is more fully disclosed.

Although the novel features which are characteristic of this invention are pointed out more particularly hereinafter, the nature of the invention will be better understood by referring to the following description, taken in connection with the accompanying drawings, in which a specific embodiment thereof has been set forth for purposes of illustration.

In the drawings:

Fig. 1 is a longitudinal section through a typical burner showing the igniter in one position for ignition;

Fig. 1a is a diagrammatic end elevation of the burner of Fig. 1 showing a representative orientation of the igniter tip in the burner air stream;

Fig. 2 is a side elevation of the igniter on a larger scale with parts broken away to show the construction thereof;

Fig. 3 is a fragmentary elevational view of the igniter tip shown in Fig. 2; and

Fig. 4 is a transverse section of the igniter tip taken on the line 4-4 of Fig. 3.

Referring to the drawings more in detail, the invention is shown as applied to a conventional fuel burner including a burner tube I!) through which the combustion air passes in the form of a rotating mass, an air register I I having air doors l2 through which this air is admitted to the burner tube, a front plate [3 at the front of the wind box, a furnace wall l4 having a throat l5 registering with the burner tube, a fuel admission ring I6 located around the burner tube l adjacent the throat l and a fuel atomizer I! which supplies other fuel for combustion. The burner may also be adapted to burn powdered fuel suspended in carrier air as is well known in the art.

The igniter, according to the present invention, comprises a body (Fig. 2) having an axial passage 2! and provided at one end with flanges 22 which are secured by bolts 23 to a casting 8! carrying the control elements to be described. At its other end the igniter body 20 carries a pair of ignition electrodes 25, one of which may be grounded to the body 20 by a cap 26, and the other of which may be insulated by and supported in a spark plug 21 which is connected by a cable 28 to the high tension side of a transformer 29 which ismounted in a housing 4| attached to the casting 24 or formed integral therewith. A sight glass 42 is shown as mounted in the body over the electrodes 25. The electrodes, sight glass, cables, casting, transformer and associated parts are sealed against the pressure in the wind box.

The body 20 is also provided with a coupling flange 30 in which a tube 3| of any desired length is secured. The tube 3| is slidable in an outer tube 43 which extends through the front plate l3, as indicated in Fig. 1, and projects at its inner end through the burner tube Ill. The tube 3| extends through a stuffing box 44 which is secured to the front plate l3 by bolts 45 and supports the outer tube 43. The tube 3| carries a tip 312 which is positioned within the burner tube 10 in the path of the air stream therein and adjacent the fuel streams to be ignited.

The tip 32 is shown in the form of a flared U- shaped housing 33 (Fig. 4) which is coaxial with the tube 3| and is closed at the two ends by plates 34. The flared side of the U-shaped member 33 is closed by a front plate 35 which is inclined to the axis of the U-shaped member 33 and of the igniter tube 31 and is provided with a central opening 36 through which the gas for combustion passes. The plate 35 is spaced from the extremities of the U-shaped member 33 and of the end plates 34 to form upstanding peripheral flanges 40 which extend entirely around the periphery of the plate 35 to shield the same from the blast of secondary air in the burner tube and to form eddy currents which serve to hold the igniter flame against the plate 35. The plate 35 is inclined in the direction of air flow towards the burner throat l5 so that the flame passing from the aperture 36 therein is directed towards the ignition zone of the burner. A lateral flange 46 extends outwardly from the side of the member 33 exposed to the rotating air stream and an end flange 41 having an upstanding lip 48 is mounted on the end plate 34 towards the air register II. The U-shaped member 33 is preferably placed at such an angle with respect to the direction of air flow through the burner tube Ill that the air passes over the curved surface of the U-shaped member 33 so as to flow in a general direction from its closed end toward the open end thereof whereby the member 33 serves to deflect the air blast away from the igniter flame projecting from the apsuitable source of current such as the usual 110 volt supply.

A valve operating handle I20 carries a pointer I I1 registering with an index carried by the index plate Ill.

It is to be understood that the tip may be located axially of the burner or may pass through the air register if desired. A specific location has been shown for purposes of illustration only.

In the construction above described, a stable flame is produced at the tip 32 which is not blown out by the blast of air through the burner tube It). While the angular position of the tip in the burner tube In may be varied somewhat, the best results are obtained when the closed end of the member 33 is pointed in the direction of air flow so that the air passes around the outside of the member 33. The flanges 40, 45 and 41 provide turbulence which retains the flame on the surface of the plate 35. Due to the diiference in depth of the flange 40 around the different portions of the periphery of the plate 35, a proper degree of turbulence is maintained over at least one portion of the plate 35 to support combustion under the different conditions of use. In certain instances it may be desirable to mount the plate 35 in a plane parallel to the axis of the tube 3| or to form the flanges 40 of the same depth around the entire plate. The construction shown, however, has been found to operate satisfactorily over a wide range of burner conditions and to maintain a stable ignition flame even when the combustion air within the burner tube Ill is turned on suddenly.

The invention is particularly adapted for use with large size industrial burners although its application is not to be restricted thereto. The igniter is not to be restricted to use with a burner, but may be used in various instances where the initial ignition at the electrodes takes place under conditions to cause incomplete combustion and the air to complete the combustion is present at the tip. Hence the device is not dependent upon the heat content of the fuel supplied as sufficient air for complete combus- .tion is supplied at the remote tip.

Various changes and adaptations may be made in the various details of construction without departing from the scope of the invention.

What is claimed is:

1. A gas igniter for use in a stream of combustion air, comprising an igniter tube for carrying a combustible gas and having a tip at its exit end to be positioned in the path of said combustion air, said tip comprising a U-shaped housing having flared side Wall having end walls and a front plate spaced inwardly from the outer ends of said side walls and forming therewith a chamber having a U-shaped transverse section, one of said end walls having a gas supply opening registering with said igniter tube with said side wall extending beyond the exit end of said tube parallel to the axis thereof, said front plate having a gas discharge opening therein through which the gas flows for combustion, said front plate being inclined in a plane intersecting the axis of said tube beyond said tip whereby the gas stream from said plate opening is directed laterally relative to the igniter tube, said side and end walls extending laterally above said front plate and thereby forming a flange therearound to shield the igniter flame from thesurrounding air stream.

2. In a gas igniter, as set forth in claim 1, a flange on and parallel to at least one edge of said side wall extending outwardly and substantially REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,124,915 Gauger July 26, 1938 2,341,266 Qeemar May 25, 1941 

